Influence of Human Leukocyte Antigen-DRB1 on the
susceptibility to rheumatoid arthritis and on the
production of anti-cyclic citrullinated peptide
antibodies in a Portuguese population
D&ário Ligeiro 1, João Eurico Fonseca 2*, Olga Abade 1, Isabel Abreu 3, Margarida Cruz 4, Patrícia Nero 4, João Cavaleiro 2, José Teles 2, Helder Trindade 1, Machado Caetano 5 and Jaime Branco 4
1 Centro de Histocompatibilidade do Sul, Portugal
2 Unidade Artrite Reumatóide, Instituto de Medicina Molecular, Portugal
3 Departamento de Imunologia da Faculdade de Ciências Médicas da Universidade Nova de Lis, Portugal
4 Unidade de Reumatologia do Hospital de Egas Moniz SA, Portugal
5 Departamento de Imunologia da Faculdade de Ci&ecincias Médicas da Universidade Nova de Lisboa, Portugal
* To whom correspondence should be addressed. E-mail: jefonseca{at}netcabo.pt.
Accepted 9 June 2006
 | Abstract |
|---|
Objective: To clarify the influence of the HLA-
DRB1 locus on the susceptibility to rheumatoid arthritis
(RA) and the production of anti-cyclic citrullinated
peptide antibodies (anti-CCP) in a Portuguese population.
Methods: 141 RA patients fulfilling the American
College of Rheumatology 1987 revised criteria for RA
were compared with 150 healthy controls. HLA-DRB1 locus
genotyping was assessed by PCR reverse probing assays
and sequence specific primers. Anti-CCP antibodies were
quantified by ELISA in RA patients.
Comparisons of the frequencies between groups were
evaluated by the two-sided Fisher's exact test and
considered significant if p<0.05.
Results: The HLA-DRB1*04 group and HLA-DRB1*10
were highly associated with RA (respectively p<0.0001
and p=0.031). High titres of anti-CCP antibodies, were
significantly associated with the presence of HLA-
DRB1*04/10.
Conclusion: The well recognized susceptibility
alleles to RA, HLA-DRB1*04, were associated to RA in
Portuguese patients. The relatively rare DRB1*10 was
also associated with RA, as it was previously described
in other Southern European countries. Both groups were
associated with high anti-CCP titres, reinforcing its
relevance to disease onset.
Keywords:
HLA, anti-cyclic citrullinated peptide antibodies, rheumatoid arthritis, shared epitope, susceptibility
